Hi Christophe, Christophe Kerello <[email protected]> wrote on Wed, 29 Apr 2020 12:13:18 +0200:
> On 4/29/20 12:06 PM, Miquel Raynal wrote: > > Hi Christophe, > > > > Christophe Kerello <[email protected]> wrote on Wed, 29 Apr > > 2020 11:41:44 +0200: > > > >> On 4/29/20 11:35 AM, Miquel Raynal wrote: > >>> Hi Christophe, > >>> > >>> Christophe Kerello <[email protected]> wrote on Wed, 29 Apr > >>> 2020 11:27:43 +0200: > >>> >>>> Hi Miquèl, > >>>> > >>>> On 4/27/20 8:22 PM, Miquel Raynal wrote: > >>>>> Hi Christophe, > >>>>> > >>>>> Christophe Kerello <[email protected]> wrote on Wed, 15 Apr > >>>>> 2020 17:57:30 +0200: > >>>>> >>>> This patch removes the constant FMC2_TIMEOUT_US. > >>>>>> FMC2_TIMEOUT_MS is set to 5 seconds and this constant is used > >>>>>> each time that we need to wait (except when the timeout value > >>>>>> is set by the framework) > >>>>>> > >>>>>> Signed-off-by: Christophe Kerello <[email protected]> > >>>>>> --- > >>>>>> drivers/mtd/nand/raw/stm32_fmc2_nand.c | 11 +++++------ > >>>>>> 1 file changed, 5 insertions(+), 6 deletions(-) > >>>>>> > >>>>>> diff --git a/drivers/mtd/nand/raw/stm32_fmc2_nand.c > >>>>>> b/drivers/mtd/nand/raw/stm32_fmc2_nand.c > >>>>>> index ab53314..f159c39 100644 > >>>>>> --- a/drivers/mtd/nand/raw/stm32_fmc2_nand.c > >>>>>> +++ b/drivers/mtd/nand/raw/stm32_fmc2_nand.c > >>>>>> @@ -37,8 +37,7 @@ > >>>>>> /* Max ECC buffer length */ > >>>>>> #define FMC2_MAX_ECC_BUF_LEN (FMC2_BCHDSRS_LEN * > >>>>>> FMC2_MAX_SG) > >>>>>> >> -#define FMC2_TIMEOUT_US 1000 > >>>>>> -#define FMC2_TIMEOUT_MS 1000 > >>>>>> +#define FMC2_TIMEOUT_MS 5000 > >>>>>> >> /* Timings */ > >>>>>> #define FMC2_THIZ 1 > >>>>>> @@ -525,9 +524,9 @@ static int stm32_fmc2_ham_calculate(struct > >>>>>> nand_chip *chip, const u8 *data, > >>>>>> u32 sr, heccr; > >>>>>> int ret; > >>>>>> >> - ret = readl_relaxed_poll_timeout(fmc2->io_base + > >>>>>> FMC2_SR, > >>>>>> - sr, sr & FMC2_SR_NWRF, 10, > >>>>>> - FMC2_TIMEOUT_MS); > >>>>>> + ret = readl_relaxed_poll_timeout_atomic(fmc2->io_base + FMC2_SR, > >>>>>> + sr, sr & FMC2_SR_NWRF, > >>>>>> 1, > >>>>>> + 1000 * > >>>>>> FMC2_TIMEOUT_MS); > >>>>> > >>>>> Is the _atomic suffix needed here? If yes it would deserve a separate > >>>>> patch with Fixes/Stable tags. > >>>>> >> > >>>> I have currently not seen any issues. So, I will remove this > >>>> modification as we will move to regmap_read_poll_timeout in patch 10. > >>>> >>>>>> if (ret) { > >>>>>> dev_err(fmc2->dev, "ham timeout\n"); > >>>>>> return ret; > >>>>>> @@ -1315,7 +1314,7 @@ static int stm32_fmc2_waitrdy(struct nand_chip > >>>>>> *chip, unsigned long timeout_ms) > >>>>>> /* Check if there is no pending requests to the NAND flash */ > >>>>>> if (readl_relaxed_poll_timeout_atomic(fmc2->io_base + FMC2_SR, > >>>>>> sr, > >>>>>> sr & FMC2_SR_NWRF, 1, > >>>>>> - FMC2_TIMEOUT_US)) > >>>>>> + 1000 * FMC2_TIMEOUT_MS)) > >>>>>> dev_warn(fmc2->dev, "Waitrdy timeout\n"); > >>>>>> >> /* Wait tWB before R/B# signal is low */ > >>>>> > >>>>> You change the timeouts from 1ms to 5s. > >>>>> > >>>>> Maybe 5s is a little bit too much IMHO but we don't really care as this > >>>>> is a timeout. However 1ms is tight. If you are changing this value > >>>>> because it triggers error (eg. when the machine is loaded), then it is > >>>>> a fix and should appear like it. > >>>>> > >>>>> Thanks, > >>>>> Miquèl > >>>>> >> > >>>> No errors currently happens. > >>>> During our stress tests, in a overloaded system, we have seen that we > >>>> could be close to 1 second, even if we never met this value. > >>>> So, to be safe, I have set this timeout to 5 seconds. > >>>> As it is just a timeout value, I have not seen any side effect. > >>>> I am using the same timeout constant to avoid to have one timeout per > >>>> cases. > >>> > >>> Something is wrong in my mind: > >>> You say you observe delays of almost up to 1 second, but the polling > >>> currently happens on 1000 us = 1ms, either you had timeouts or I > >>> misread something? > >>> > >>> Thanks, > >>> Miquèl > >>> >> > >> Hi Miquèl, > >> > >> My fault. For this polling, we never met 1 ms. > >> The 1 second observed was on the sequencer when we read/write a page (as > >> it the same timeout value that is used) > > > > OK I get it. So perhaps you can give these details in the commit log to > > explain why you use 5 seconds instead of one. > > > > Thanks, > > Miquèl > > > > Hi Miquèl, > > A proposal could also be to split this patch: > - a first patch that is using only one timeout value. > - a second patch that is increasing the value to 5 seconds. > > Regards, > Christophe Kerello. Given the situation, both are fine as long as everything is clearly explained in the commit log :) Thanks, Miquèl
